• Carbon letters
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• v.7 no.2
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• pp.105-113
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• 2006

The electro-chemical removal (ECR) of water pollutants by metal-ACF electrodes from wastewater was investigated over wide range of ECR time. The ECR capacities of metallic ACF electrodes were related to physical properties such as adsorption isotherm, surface area and pore size and to reaction time. Surface morphologies and elemental analysis for the metal supported ACFs after electro-catalytic reaction were investigated by scanning electron microscopy (SEM) and energy disperse X-ray (EDX) to explain the changes in adsorption properties. The IR spectra of metallic ACFs for the investigation of functional groups show that the electro-catalytic treatment is consequently associated with the removal of pollutants with the increasing surface reactivity of the activated carbon fibers. The metal-ACFs were electro-catalytically reacted to waste water to investigate the removal efficiency for the COD, T-N, $NH_4$-N, $NO_3$-N and $NO_2$-N. From these removal results of the piggery waste using metallic ACFs substrate, satisfactory removal performance was achieved. The removal efficiency of the metallic ACFs substrate was mainly determined by the properties of the material for adsorption and trapping of organics, and catalytic effects.

• Progress in Superconductivity
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• v.4 no.2
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• pp.157-161
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• 2003

We have performed the electrochemical method to fabricate high temperature superconducting (TlPbBi) -(SrBa)-Ca-Cu-O films. The precursors of the superconducting sample were codeposited at a periodic pulsed-potential cycle (1 second at -4V and 1 second at -1V) on a silver substrate. The variation of structure, microstructure and element were analysed by ICP and SEM techniques. The specimens were consisted predominantly of the Tl-1212 phase and have a transition temperature of 80～87 K in low magnetic field. It was showed that each grain has the stoichiometric ratio of $T1_{0.7}$Pb_$Bi_{0.3}$ $_Sr{0.1}$ $Ba_{2.4}$ $Ca_{0.2}$ $Cu_{1.2}$ $2.5/O_{x}$ by EDX analysis.sis.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.124-133
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• 2003

Ti-25Al-xNb (x=0, 3, 7, 11, 13 at. %) alloys and 18 vol. % TiB/(Ti-25Al-11Nb) metal matrix composite were fabricated by spark plasma sintering process at 900-120$0^{\circ}C$. Microstructural characteristics of the sintered bodies were identified by SEM, EDX analysis, X-ray diffraction, and differential scanning calorimeterric method. $Ti_3Al$ alloy was consisted of equiaxed $\alpha_2$ phase. $Ti_3Al-Nb$ alloys and the matix of TiB/(Ti-25Al-11Nb) metal matrix composite had the morphology that O phase was precipitated at the grain boundary of $\alpha_2$phase. Volume fraction of O phase and hardness were depended on the concentration of Nb in $Ti_3Al-Nb$ alloy, Rule of mixing could be applied to hardness and Young's modulus of 18 vol. % TiB/(Ti-25Al-11Nb) metal matrix composite.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.66-74
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• 2004

The sliding wear behavior of $ZrO_2-22wt\%MgO\;(MZ)\;and\;ZrO_2-8wt\%Y_2O_3\;(YZ)$ deposited on a casting aluminum alloy with bond layer (NiCrCoAlY) by plasma spray against an SiC ball was investigated under dry test conditions at room temperature. At all load conditions, the wear mechanisms of the MZ and the YZ coatings were almost the same. The wear mechanisms involved the forming of a smooth film by material transferred on the sliding surface and pullout. The wear rate of the MZ coating was less than that of the YZ coating. With an increase normal load the wear rate of the studied coatings increased. The SEM was used to examine the sliding surfaces and elucidate likely wear mechanisms. The EDX analysis of the worn surface indicated that material transfer was occurred from the SiC ball to the disk. It was suggested that the material transfer played an important role in the wear performance.

• Journal of Powder Materials
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• v.18 no.6
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• pp.517-525
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• 2011

In this study, the used DOCs, which could remove the air pollutants such as CO and HC in the exhaust gas from diesel vehicle, were remanufactured by various conditions. Their catalytic performances and characterization were also investigated. The remanufacturing process of the deactivated DOCs includes high temperature cleaning of incineration, ultrasonic cleaning for washing with acid/base solutions to remove deactivating materials deposited to the surface of the catalysts, and active component reimpregnation for reactivating catalytic activity of them. The catalytic performance tests of the remanufactured DOCs were carried out by the diesel engine dynamo systems and chassi dynamo systems in CVS-75 mode. All prepared catalysts were characterized by the optical microscopes, SEM, EDX, porosimeter and BET to investigate correlations between catalytic reactivity and surface characteristics of them. The remanufactured DOCs at various conditions showed the improved catalytic performances reaching to 90% of fresh DOC, which is attributed to remove the deactivating materials from the surface of the used DOC through the analysis of catalytic performance test and their characterization.

• Journal of Korea Foundry Society
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• v.18 no.6
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• pp.534-540
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• 1998

6061Al-matrix composite with TiNi shape memory fiber as reinforcement has been fabricated by Permanent Mold Casting to investigate the mechanical properties of the smart composites. The composites have showed good interface bonding as a result of the analysis of SEM and EDX. The smartness of composite is given due to the shape memory effect of the TiNi fiber which generates compressive residual stresses in the matrix material when heated after being prestrained. The tensile strength of the composites was tested at temperatures between $90^{\circ}C$ and room temperature with increasing amount of pre-strain, and it showed that the tensile strength at $90^{\circ}C$ was higher than that of the room temperature. Especially, the tensile strength of the composite increases with increasing pre-strain. It showed that hardness of matrix was higher than that of common 6061Al alloy.

• Tribology and Lubricants
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• v.25 no.2
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• pp.120-124
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• 2009

In automobile chassis system, several environmental factors weaken durability of automobile's components. The environmental factors are temperature, humidity, intensity of radiation and dust particle inflow. Especially, dust particle inflow leads to increase in friction and wear of automobile's components. The wear of automobile's component leads to increase in noise and exerts a bad influence on life of components. In this study, dust particles were investigated for study on the influence of dust particle inflow. Dust particles are collected on urban area, rural area and highway in China. The size of dust particle is analyzed using the image plus program, and the element of dust particle is analyzed using the SEM and EDX. The elements of dust particle are $SiO_2$ and $Al_{2}O_{3}$. The other elements(Na, Ca, Cl etc..) are detected on urban area and highway.

• Clean Technology
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• v.19 no.3
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• pp.347-350
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• 2013

Desorption characteristics for ions adsorbed onto sericite was performed by means of $HNO_3$ solution which was selected as the best desorbing agent in the previous work. Elution of nickel ions adsorbed onto sericite using $HNO_3$ solution was confirmed by means of scanning electron microscopy (SEM) & energy dispersive X-ray spectroscopy (EDX) analysis. Desorption efficiency for nickel ions was 100% at the 20 mM of concentration. Also, nickel ions was completely desorbed within 1.0 of S/L (mg/mL) ratio which is defined as the ratio of adding amount of adsorbent and volume of desorbing agent and desorption process was quickly carried out within 60min. Finally, removal efficiency of reused sericite for nickel ions was constantly maintained until the 4th cycle.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.6
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• pp.482-489
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• 2008

Ti-Cr alloys consist of BCC solid solution, C36, C14 and C15 Laves phase at high temperature. Among others, the BCC solid solution phase was reported to have a high hydrogen storage capacity. However, activation, wide range of hysteresis at hydrogenation/dehydrogenation, and degradation of hydrogen capacity due to hydriding/dehydriding cycles must be improved for its application. In this study, to improve such problems, we added a Nb. For attaining target materials, Ti-10Cr-xNb(x=1, 3, 5wt.%) specimens were prepared by arc melting. The arc melting process was carried out under argon atmosphere. As-received specimens were characterized using XRD(X-ray diffraction), SEM(Scanning Electron Microscopy) with EDX(Energy Dispersive X-ray) and TG/DSC(Thermo Gravimetric Analysis/Differential Scanning Calorimetry). In order to examine hydrogenation behavior, the PCI(pressure-Composition-Isotherm) was performed at 293, 323, 373 and 423K.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.128-128
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• 1999

산소이온 전도체로 잘 알려진 Yttira-Stabilizd Ziroconia(TSZ)는 연료전지, oxygen pumps, chemical gas sensor 등 다양한 electrochemical divices에 이용되는 고체 전해질의 하나이다. 특히 YSZ는 oxygen 및 oxygen과 평형상태에 있는 gas들을 검출하는 sensor의 electrolyte로서 가장 많이 쓰이고 있다. 현재 상용화되어 있는 YSZ Sensor는 전통적인 bulk 형태의 ceramic으로 제작된 것으로 충분한 ionic conductivity를 얻기 위해서는 $600^{\circ}C$이상의 operating temperature를 필요로 하나 YSZ를 박막으로 제조시 낮은 operating temperature를 뿐만 아니라 sensor의 소형화, 낮은 ohmic loss 및 다양한 응용이 가능한 장점을 가질 수 있다. 본 실험에서는 산소 이온 전도체로서 8mol%-YSZ 고체전해질을 RF-magnetron bias sputtering 법을 이용하여 증착하였다. 제조된 YSZ 박막을 이용한 산소감응 센서셀 구조는 SiO2/Ni-NiO/Pt/YSZ/Pt-기판이다. 센서셀의 정상상태에서의 기전력(electromotive force ; EMF)을 산소분압(Po:1.013$\times$103Ta ~1.013$\times$105Pa)과 측정온도(30$0^{\circ}C$~$700^{\circ}C$)를 변화시키며 측정하였다. 이론적인 기전력과 측정값 사이의 편차는 Po:1.565$\times$104Pa 이하의 산소분압에서는 컸지만 이 이상의 분압에서는 이론치에 근접한 값을 가졌다. 증착한 YSZ와 Ni-NiO 박막의 구조는 X-ray diffractometer(XRD)를 이용하여 결정구조를 알아 보았고, TSZ 박막의 표면 morphology 관찰은 Scanning electron microscopy(SEM) 이용하였다. 박막의 조성분석은 X-ray energy dispersive analysis(EDX)을 사용하였다.